Former Tory leader Iain Duncan Smith is among the 70 signatories of the letter.
Photograph: Handout/Getty Images

The BBC is failing in its duty to be impartial over Brexit, a group of parliamentarians has claimed. In a letter to senior BBC figures, they said the broadcaster had characterised Britain as xenophobic and focused too much on regretful leave voters.

The 76-strong group, made up mainly of Conservative MPs and including former cabinet ministers, warned the BBC’s director general, Tony Hall, and the incoming chair of its new governing body, David Clementi, that the broadcaster’s future might be in jeopardy if it was not seen as neutral.

“The corporation’s focus on ‘regretful’ leave voters, despite there being no polling shift towards remain since the referendum, has led some to believe it is putting its preconceptions before the facts,” they wrote. “Meanwhile, the posturing and private opinions of EU figures are too often presented as facts, without the vital context that they are talking tough ahead of the exit negotiations.”

The 72 MPs and four peers added that “many leave-voting constituencies have felt that their views have been unfairly represented” by the BBC, an issue they said was “weakening the BBC’s bond with the 52% who voted leave and all who wish to make a success of the decision made”.

A BBC source dismissed the criticism, insisting that the broadcaster was impartial and saying it had “included a balanced range of voices from across the political spectrum and on both sides of the debate” when covering the referendum. “It is notable the letter is general in nature with no specific examples,” the source said.

Ahead of last June’s vote, BBC staff were issued with a series of guidelines designed to ensure balance across the broadcaster’s output during the formal campaign period.

Among the signatories to the letter were the former Tory leader and work and pensions minister Iain Duncan Smith, as well as the former environment secretary Owen Paterson and Northern Ireland secretary and transport minister, Theresa Villiers. It was coordinated by the Tory MP and former BBC and Independent journalist Julian Knight, who backed remain.

They told Hall and Clementi: “It particularly pains us to see how much of the economic good news we’ve had since June has been skewed by BBC coverage which seems unable to break out of pre-referendum pessimism and accept new facts.

“Some of the signatories of this letter shared many of the concerns about the economic impact of Brexit, but all are delighted to find forecasts of immediate economic harm were at best misplaced. So-called ‘despite Brexit’ reporting may be expected of a partisan press, but licence fee-payers have the right to expect better.”

They added that the BBC was an influential force in shaping the view of Britain from abroad and feared that it was “misrepresenting our country either as xenophobic or regretful of the leave vote”. That, they claimed, could “undermine our efforts to carve out a new, global role for this country”.

A BBC spokesperson said: “While we are always live to our critics and understand that passions are running high on all sides of the debate, it is the job of the BBC to scrutinise and analyse the issues on behalf of the public and to hold politicians to account across the political spectrum. That is what the BBC has been doing. It is what the BBC will continue to do. It is precisely because of this that the public trusts the BBC.”

The letter was signed by 60 Tory MPs and two Conservative peers, as well as three Labour MPs, eight DUP MPs, two DUP peers and Ukip’s only MP. Writing for Conservative Home, Knight insisted he was not “BBC baiting”. “[I] firmly believe it’s the greatest repository of media talent anywhere in the world,” he said.